Depth Dependence of Neutron-Induced Errors in 3-D NAND Floating Gate Cells

The sensitivity of vertical-channel 3-D NAND Flash memories to wide-energy spectrum neutrons is investigated as a function of cell depth in the pillars. Errors are found to be less numerous at the center of the pillar, mainly due to the impact of top-to-bottom tapering on the electrical characteristics of the floating gate (FG) cells and, to a smaller extent, to a different generation of neutron secondaries as a function of depth.